Overview

Zinc is an essential mineral that our bodies need in small amounts to function properly. Just some of the fundamental processes zinc is involved in are protein & DNA production, cell division, and wound healing. However, zinc is better known for playing a critical role in the function of the immune system.

Indeed, many people believe that supplementing zinc can help ward off colds and other infections and illnesses. The only caveat is that zinc supplements are unlikely to do much if you already get enough zinc from your diet.

Although zinc deficiency is relatively rare in the developed world, certain populations – such as the elderly and vegetarians – do have an increased likelihood of not getting enough zinc. As such, they might see improved immune system function from zinc supplementation.

Oysters, red meat, and chicken are great sources of zinc, in addition to other protein-rich foods such as nuts and seafood.

How Zinc Might Help With Immunity

Supporting optimal immune function

Zinc plays a critical role in virtually all aspects of the immune system. Zinc is needed for optimal function of the many different types of white blood cells that protect the body from illness and infection, in addition to cytokine production, phagocytosis, and other immune system processes.1 Even mild zinc deficiency can weaken the immune system, whereas severely zinc-deficient individuals suffer from constant infections that could even lead to death as early as 25 years of age.

Antioxidant activity

Activation of the immune system results in increased generation of reactive oxygen species (ROS), which can in turn in damage immune system cells and processes. As an antioxidant compound, zinc can help neutralize this damage, indirectly improving immune system function.2

As many as 50% of alcoholics have low zinc levels because the ethanol present in alcohol decreases zinc absorption and increases its excretion.3

Zinc Immunity Uses & Benefits

Given it’s essential roles in the human body, zinc is supplemented to help with everything from testosterone production to vision loss. Similar to vitamin C, zinc is also commonly used to ward off cold and flu infections.

There is some scientific evidence that zinc can help with colds. In terms of boosting overall immune function, however, it seems that zinc only helps individuals with low zinc levels, such as older adults.

While zinc does appear to have some use as an immunity booster, taking too much zinc can have the opposite effect. One study, for example, reported that men taking 300 mg of zinc twice daily for 6 weeks had an impaired immune response.4

Research

Human Research

Human trials confirm that zinc supplementation can improve immunity in the elderly, and help ward off the common cold.

This randomized, double-blind, placebo-controlled study tested the immunity benefits of zinc supplementation in elderly participants. Fifty healthy adults (aged 55-87) received either zinc gluconate (45 mg) or placebo daily for 12 months. The trial found that the subjects had naturally lower zinc levels than younger adults, and that supplementation raised zinc levels along with a significant reduction in occurrence of infections and production of tumor necrosis factor alpha, a cytokine that promotes inflammation.

This study examined the effect of zinc supplementation on the immune system of older adults. Fifteen people (aged older than 70) were given zinc sulfate (440 mg) daily for month and compared to 15 supplemented individuals. The study reported significant improvement of immune function, as shown by higher number of T cells, delayed hypersensitivity reactions, and antibody response to a vaccine.

The researchers concluded that “the addition of zinc to the diet of old persons could be an effective and simple way to improve their immune function.“6

This systematic review sought to explain the mixed results of 13 studies looking at zinc use for the common cold. The researchers hypothesized that the reason some studies showed no benefit was because the zinc dosage was too low. They found that all 8 studies that used high doses (75+ mg) of zinc reported a significant reduction (20-42%) in the duration of colds.

The researchers concluded that “Many trials with daily zinc doses of over 75 mg have found significant reduction in the duration of colds.“7

Dosage for Immunity

Research suggests that around 45 mg zinc gluconate or 440 mg zinc sulfate can boost immunity

Zinc doses of 75 mg or more appear to be effective for helping with colds

Zinc acetate may be more effective for warding off colds than zinc gluconate

Supplements in Review Says

Zinc gluconate or zinc acetate 45-100 mg daily for immunity.

We recommend zinc for helping with cold infections, and for older adults looking to boost their overall immunity. Older individuals tend to have lower zinc levels, and research confirms that zinc deficiency can weaken the immune system.

Zinc gluconate or acetate are ideal. Most zinc supplements come in one of these two forms. If you’re looking for general immune system support zinc doses between 45 and 75 mg are sufficient; for getting over a cold, doses higher than 75 mg work best.